研究顯示,不可見的紅外線可能傷害視網膜。

綠光雷射筆.jpg 


Green laser pointers may emit high levels of invisible and potentially dangerous infrared light, a new study says.

Aug. 6, 2010 -- Green laser pointers may emit high levels of invisible and potentially dangerous infrared light, a new study says.

Researchers report that green laser pointers deliver light that is brighter to the eye than red lasers, but the infrared light emitted by some inexpensive models could damage the retina of the eye.

Charles Clark, PhD, of the National Institute of Standards and Technology (NIST), led a research team measuring the output of several green laser pointers. The researchers bought three low-cost green laser pointers that had been advertised to have a power output of 10 milliwatts.

Researchers say one of the units emitted dim green light, but delivered infrared levels of nearly 20 milliwatts.

That’s enough to cause damage to the retina before a person is even aware of the invisible light.

Tests using several other laser pointers found intense infrared emissions in some, but not all, units.

According to a NIST news release, the problem is the result of inadequate procedures in the manufacturing process. The problem could be solved by building on an inexpensive infrared filter at the end of the laser that would substantially reduce infrared emissions.

Such filters exist in modern digital cameras and the more expensive green laser pointers, but they are commonly left out of inexpensive models.

Owners of green laser pointers should never point them at anyone’s eyes or aim them at windows, which could reflect infrared light back to the user.

The research is detailed in a publication called NIST Technical Note 1668. The NIST is part of the Department of Commerce.

WebMD Health News 
by Bill Hendrick 
Reviewed By Laura Martin

Last Modified: 2010/8/6 下午 04:36:30

c 2010 WebMD, LLC. All rights reserved.

24drs.comAug. 6, 2010 -- 最新研究顯示,綠色雷射筆可能發射出大量不可見且可能有危險的紅外線。
  
  研究人員表示,綠色雷射筆對眼睛傳送出比紅色雷射更亮的光,但藉由某些價格低廉的模式所發射出的紅外線會傷害眼睛的視網膜。
  
  全國標準與科技協會(NIST)的Charles Clark博士領導研究團隊測量數種綠色雷射筆的產出,這些研究人員買三種低價、以輸出功率10毫瓦特為廣告的綠色雷射筆。
  
  研究人員表示,其中一種發射微暗的綠光,但傳送出的紅外線量近20毫瓦特。在你注意到不可見光之前,即已足以傷害視網膜。
  
  使用數種其他雷射筆所做的測試發現,有些產品會發射強烈的紅外線,但不是全部都會如此。
  
  根據NIST的新聞稿指出,問題出在製造流程中不適當的程序所造成,可以藉由在雷射末端用便宜的紅外線濾器,大量減少紅外線發射來解決這個問題。
  
  現在的數位相機與較昂貴的綠色雷射筆中都有這種濾器,但便宜的東西通常沒有。
  
  使用綠色雷射筆的人應該絕不會用它指向別人的眼睛或是對窗戶描準,因為窗戶會把不可見光反射到使用者身上。
  
  這篇研究的詳細說明刊載在NIST技術說明1668上,NIST是商務部的下屬單位。

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